A Scoping Review of Transgender Policies in the 15 Most Commonly Played UK Professional Sports

Introduction: There has been much debate recently on the participation of transgender and gender-diverse (TGD) athletes in sport, particularly in relation to fairness, safety and inclusion. The 2021 IOC Framework on Fairness, Inclusion and Non-discrimination acknowledges the central role that eligibility criteria play in ensuring fairness, particularly in the female category, and states that athletes should not be excluded solely on the basis of their TGD identity. Aims: To identify policies that address TGD athlete participation in the 15 major United Kingdom (UK) sporting organisations and to summarise the evidence for each of these policies. Methods: A scoping review of TGD policies from the 15 major UK sporting organisations. Results: Eleven of the governing bodies had publicly available TGD policies. Most of the sporting associations drew guidance from the official 2015 IOC Consensus Meeting on Sex Reassignment and Hyperandrogenism, particularly with regard to physiological testosterone levels. Many organisations referenced their policies as a guide for decision making but stated that they ultimately made case-by-case decisions on an athlete’s eligibility. Relevant considerations not addressed in most policies included pre- versus post-pubertal athletes, justification for testosterone thresholds, the length of time out of competitive action (if any) for transitioning athletes, the irreversible advantage from male puberty (if any), the responsibility for and frequency of follow up for hormonal testing and the consequences for athletes outside set testosterone limits. Conclusions: There is a lack of consensus among the top 15 UK sporting organizations relating to elite sport participation for TGD athletes. It would be useful for sport organizations to work together to develop greater standardization/consensus for TGD athlete policies, taking into consideration fairness, safety and inclusion in each sport.


Introduction
Fair, inclusive and non-discriminatory sport participation for all athletes, including transgender and gender-diverse (TGD) athletes, is currently a very topical issue within sport medicine and society in general. In 2021, the United Kingdom (UK) sport councils produced a document reviewing transgender inclusion in domestic sport (Guidance for Transgender Inclusion in Domestic Sport) [1]. This document concluded that there is no single solution to the issue, instead offering guiding principles to promote fairness, safety and inclusivity, but it recognised the presence of retained male advantage and noted that a decision should be made by sporting federations between fairness and inclusivity.
The International Olympic Committee (IOC) recently released a framework for fairness, inclusion and non-discrimination on the basis of gender identity, putting greater emphasis on inclusion, although it deferred practical guidance and decision making to individual sports based on their specific circumstances [2]. Although some regulation has existed since the 1940s [3][4][5][6], consideration of TGD athlete participation and scientific research in the area were limited until recently. This review focused on policies related to transgender athletes and did not consider policies related to intersex athletes or those with differences in sexual differentiation (DSD).
Sport participation for all needs to be promoted, as sport provides a plethora of benefits for both mental and physical health [29,30]. Indeed, TGD athletes must be able to participate in and have access to sport, and barriers to them doing so, in whichever category is determined most appropriate for the sport, should be addressed [2]. The barriers to subsequent participation by athletes in the female category, including TGD athletes, due to fairness, safety or other issues also need to be considered as part of this discussion [2, 5,12].

Aims
To understand how sporting organisations are navigating these issues, we aimed to conduct a scoping review of current guidelines from the 15 major UK sporting organisations with the highest participation numbers in order to:

1.
Determine those that have an existing TGD athlete policy; 2.
Review their specific guidance on eligibility (including testosterone-based regulations); 3.
Summarise the policies in different sports; 4.
Map the evidence gaps in the TGD policies across the different organisations.

Methods
A scoping review was considered the most appropriate methodological approach to address the research question. A scoping review is defined as an exploratory project that systematically maps the literature available on a topic, identifying key concepts, theories, sources of evidence and gaps in the literature [31,32]. Compared to systemic reviews, scoping reviews make it possible to investigate a less specific research question and work to inform future research [33]. This scoping review was based on the six-step methodological framework outlined by Arksey and O'Malley and informed by Levac et al. [34,35]. The Preferred Reporting Items for Systemic Review and Meta-Analysis (PRISMA) protocol was followed and the PRISMA extension for scoping reviews (PRISMA-ScR) checklist completed [31]. Throughout this review, we define transgender athletes as per the IOC; that is, "Someone who identifies with a gender that is different from the sex that they were assigned at birth. A transgender man is a man who was assigned female at birth; a transgender woman is a woman who was assigned male at birth" [2]. This review exclusively focuses on transgender athletes, without consideration for intersex athletes or athletes with differences in sex development (DSD) or related disorders.

Stage 1: Identifying the Research Question(s)
The following research objective was addressed in this report: to identify policies that address TGD athlete participation in the 15 major United Kingdom (UK) sporting organisations and to summarise the evidence for each of these policies.
To be included in this review, the sports had to be widely participated in at an amateur level within the UK. Participation levels were taken from the Sport England website via the Active Lives survey, as well as from independent reports from Harris Interactive, Statista and the Ipsos MORI sports tracker [36][37][38][39][40]. Polls from unofficial sources, such as major sporting magazines or online fan websites, were also reviewed, as were the Wikipedia pages for "Sport in England" and "Sport in the United Kingdom".

Stage 2: Identifying Relevant Policies
Searches for TGD policies among the 15 major UK sports organisations were carried out from inception to December 2021 to find relevant guidelines to include in this review. This was undertaken by first identifying the sports with the highest levels of participation and then identifying the official governing bodies for each sport (both UK-wide and nationally) through simple internet searches. Following this, each organisation's official website was searched for a transgender policy, and searches were also undertaken using search engines (Google search, Google Scholar). Where a policy was not identified or publicly available, direct inquiry with the organisation was attempted.

Stage 3: Policy Selection
TGD guidelines were accessed either via the official organisation websites or through a request addressed to a relevant representative. When separate organisations were present for the same sport in England, Scotland, Northern Ireland and Wales (for example, rugby union), the England guidelines were reviewed, as England represented the largest population of amateur athletes that would typically use such guidelines. Searches were carried out by MMcL and checked by NH, with AM reviewing any disagreements.

Stages 4 and 5: Charting the Data and Collating, Summarizing and Reporting Results
The following data were extracted for each sport: the primary governing organisation for that sport; the sports played within the remit of the organisation; the official TGD policy of the association; testosterone cut-off levels for transitioning athletes and their rationale, taking into consideration the different demands of the sports; the length of any required time out of competition during/post-gender-affirming therapy; the hormone eligibility evidence required by the governing body for sports participation; regulations around child or adolescent TGD participation; and specific case-by-case guidance for individual TGD athletes. Information was recorded using Microsoft Excel.

Sporting Organisation Guidelines
Data analysed for each sport, relevant UK sporting organisations and sports played within the organisations are summarised in Table 1. Although individual breakdowns of gender participation are not provided by the organisations, we know that there is generally a consistently higher proportion of male athletes engaging in amateur sport [37,41]. Data taken from an analysis of the Taking Part survey provide the proportions of male/female participants in popular sports in the UK [41] and are also included within Table 1. This information was available for 8/15 of the included sports. Where available, information on the specific guidance and rules that each organisation based their policy on is included. Table 2 summarises the contents of the sport-specific guidelines for each organisation. As many policies are adopted from the IOC's 2021 (and, before that, 2015) position [2], this has also been included for reference.  Case-by-case decisions. "The Expert Panel may request that a trans or non-binary person whose gender identity was not female at birth, who is undergoing hormone treatment and is intending to compete in the women's category, resubmit their declaration annually to confirm they are still undergoing treatment." Eligibility for national teams and international competition differs from this domestic policy  To require surgical anatomical changes as a pre-condition to participation is not necessary to preserve fair competition and may violate human rights * Largest and most representative organisation in the United Kingdom. 1 As of 1 July 2022, international guidance from the UCI has altered their stance to reflect a lower maximum plasma testosterone of 2.5 nmol/L and extended their transition period for low testosterone from 12 to 24 months with respect to transgender female athletes [42]. Twelve of the fifteen governing bodies had an official TGD policy (even if that policy was just to state that there were no interventions required for participation), of which eleven were publicly available (with the 2011 Rugby League guideline being referenced in an alternative publication but not available despite attempts to contact the governing body directly). Of these 12, all had pre-requisites for trans women athletes (testosterone monitoring, written medical documentation or clearance before a panel (Table 2)). Five of the twelve had separate guidance for adolescent/pre-pubescent versus post-pubertal athletic participation. Seven drew guidance from the official IOC Statement on Transgender Guidelines [44], particularly in reference to physiological testosterone levels. Many (8/12) organisations included the disclaimer that they made "case-by-case" decisions on an athlete's competitive eligibility, using their policies only as a guide for decision making. The official 2021 IOC Framework also states that all athletes are approved on a case-bycase basis in their guidance, with wordings being very similar to this policy across each sport. The additional criteria assessed in case-by-case decisions are not discussed in any policy (with the exception of badminton, for which the guidance states that the duration of hormonal therapy/transitioning would be assessed individually to ascertain adequacy). Several policies have less strict restrictions on participation at the recreational/amateur level, including athletics, tennis and cycling. For athletics, the governing body, United Kingdom Athletics (UKA), specifies that restrictions do not apply to training, friendly/fun runs or mass participation events, such as charity events; restrictions are only applied to competitions where qualifying marks, selection standards and records are set. British Cycling stipulates that there are no regulations for recreational activities, and the Lawn Tennis Association states that recreational and friendly matches are exempt. Other policies do not specifically comment on training, recreational activity within clubs or friendly matches; therefore, their stances are unclear. Only two policies (Rugby Football Union and British Rowing) mention the specific involvement of or consultation with a medical professional/medical officer in their TGD policy development. Three of the policies are currently under review.
In two of the three sports without TGD policies, it could be proposed that physical differences in competitors are unlikely to result in harm to individuals or fellow competitors or involve a significant physical competitive advantage for males ("sex-affected sports"). These sports are snooker/billiards and motorsports. The third, however, is boxing; the British Boxing Board of Control has no official TGD participation policy. Although the Rugby Football League (RFL) refers to a TGD policy published in 2011, it is not publicly available and was not made available when we emailed the RFL contact on their website.
Notably, where policies exist, a definition of transgender is often provided to outline the remit of the policy. Policies relate to transgender as opposed to intersex athletes or athletes with DSD.

Discussion
This is the first scoping review to summarise the TGD policies of the 15 most widely played sports in the UK, detailing the individual protocols of each sporting governing body for TGD athletes. Our review showed that 80% (12/15) of the organisations have an official TGD athlete participation policy. The policies are highly heterogeneous, with different requirements and time frames for TGD athletes to be included in a class other than that of their biological sex. The majority of policies rely heavily on the official IOC Statement on Transgender policies [2,44], stating they will refer to it when making decisions on individual athletes and generally adopting a case-by-case approach when assessing TGD athletes. Only 38% (5/13) of the guidelines have separate guidance for adolescent or child athletes. There appears to be no difference in the rigour of assessment between non-contact and contact sports and, indeed, boxing has no current TGD policy. Criteria were globally much stricter for trans female athletes wishing to participate in the female category versus trans male athletes wishing to compete in the male category. Finally, although serum testosterone levels were specified for four sports (<2.5 nmol/L for cycling, <5 nmol/L for rugby union and rowing, and <10 nmol/L for badminton), for participation in the female events, few details are provided on what sporting organisation is responsible for the testing, the parameters around the testing and the steps taken if the athlete's testosterone level is outside these stated ranges. Three sports (athletics, cycling and tennis) have more relaxed TGD policies for sport participation at the recreational level.

Adolescent and Child Participation
Five sports (cricket, rowing, cycling, golf and tennis) had pre-puberty guidelines for TGD sport participation, with most sports stating that puberty occurred from 16 years of age onwards. However, some children, including those under 16 years of age, may identify as TGD [45], and thus sport organisations may wish to formally address this within their TGD policies. The Guidelines for Creating Policies for Transgender Children in Recreational Sports, the national policy of the United States (US), assert that no hormonally based advantage exists for sexes prior to puberty [46], although other authors contend that there is pre-pubertal difference, in keeping with the concept of "mini-puberty", as well as genes exclusively related to the Y-chromosome [47][48][49][50]. Furthermore, the onset of puberty shows some variance among individuals, as well as the sexes, and, therefore, it is difficult to set an arbitrary age limit via which athletes could be considered pre-and post-pubertal. Puberty is, however, rare before the ages of nine and eight in males and females, respectively [51][52][53]. There is, therefore, a need for TGD policies in sport to address pre-and post-pubertal athletic participation.

Anthropometric Sex Differences and Impact on Sport Performance
Although physical sex differences are noted (some in athletic and some in non-athletic populations), and certain sports seem to preferentially select at the extremes of the distribution for a trait (e.g., height in basketball), it is plausible that an anthropometric advantage could exist for TGD athletes in their sport. TGD policies should investigate this further within their cohort of athletes to determine whether it is the case. Similarly, when an athlete has increased muscle mass or body size relative to peers in their gender (outside of what can be observed within the given sex), they have greater potential to inflict injuries on others, potentially compromising safety [12].
Moreover, it has been reported that muscle nuclei that have been developed during periods of testosterone therapy remain in the muscle even after drug cessation and potentially confer a lifelong muscle-building advantage [54][55][56]. Therefore, although it is difficult to measure the magnitude of the advantage that might be obtained in a given sport for a range of physical metrics that differ between the sexes, these performance advantages are present partly due to androgenic male puberty and are not dependent on current circulating testosterone. Thus, TGD policies should consider whether the athlete has undergone puberty and what affect this could have on their participation in their chosen sport, as well as considering circulating testosterone levels.

Transgender (Trans Women/Trans Female) and Gender-Diverse Athletes with Suppressed Testosterone
Our research indicated that, when specified, testosterone levels lower than 2.5 nmol/L for 24 months (cycling-UCI rules) and lower than 5 nmol/L for at least 12 months (rugby and rowing) are considered general cut-offs among UK sport organisation for trans women's participation in female sport, although badminton guidelines specify a testosterone value lower than 10 nmol/l, in keeping with the 2015 IOC guidance [44]. The UCI has recently reduced its testosterone cut-off level to 2.5 nmol/L for two years [42], and the UK national governing body policy is likely to follow. However, adult males generally have testosterone levels at least 15 times higher than females of a similar age [57], and the 95% confidence interval for circulating testosterone in healthy premenopausal adult females is 0-1.7 nmol/L [57]. Thus, sport organisation need to consider what testosterone levels will apply to their sport and what lengths of time out of competition will apply. These findings may be particularly relevant for strength-based (requiring running and jumping) and contact sports; for example, rugby, football, boxing and martial arts. Different considerations may be needed for sports where physiological differences or potential safety concerns are not an issue and inclusivity can be prioritized.
Another important issue to consider for competitive, strength-based sport participation is non-compliance with the proposed upper limit for serum testosterone levels as measured by liquid chromatography-mass spectrometry. Only the IOC provides guidance for non-compliance with these limits [44], enforcing 12 months of exclusion following a supraphysiological result. However, little detail is provided on how this testing will be undertaken and whose responsibility it is to undertake it. The World Anti-Doping Association (WADA) has produced a physician guide for TUE applications for transgender athletes (accessed at https://www.wada-ama.org/en/resources/therapeutic-use-exemption/tuephysician-guidelines-transgender-athletes#resource-download, accessed on 10 January 2023) and suggests testosterone testing at least 1-2 times per year by the treating physician.

Transgender (Trans Men/Trans Male Athletes) and Gender-Diverse Athletes on Testosterone Therapy
Less guidance exists amongst UK sporting organisations for the participation of trans men/trans male athletes on testosterone therapy, with many groups requiring either no information (hormonal or otherwise) or simply a written declaration. The Football Association is the only organisation requesting hormonal levels and requiring them to be within the male range. Exogenous androgens are known to be performance-enhancing for all athletes and are, therefore, on the WADA's Prohibited List [58]. In hypogonadal male athletes, testosterone replacement therapy has often been found to result in testosterone levels above the upper range of normal [59], and its prevalence in mainstream sports has recently come under scrutiny for potentially conferring an advantage [60][61][62].
Beyond this, exogenous testosterone therapy may also confer an advantage within physiological levels [63][64][65], which requires further consideration. In males, testosterone levels fluctuate with the circadian rhythm and in response to disease, stress (both physical and mental), increasing age and other stimuli [66,67]. In some sports, rapid weight loss and low body fat levels are common prior to competitions (for example, in boxing) [68,69], with known effects on testosterone levels, as part of the recognised spectrum Relative Energy Deficiency in Sport (RED-S) [70][71][72][73]. Reductions in testosterone levels are observed when body fat is reduced below a certain level [74,75]. In trans male athletes receiving exogenous testosterone supplementation, such fluctuations or reductions pre-competition will not be observed, nor will diurnal fluctuations [76][77][78][79]. With dose-response effects from testosterone on strength, power, muscle size and body fat percentages within physiological ranges being demonstrable [57,65], athletes can titrate their levels to consistently remain at the upper limit of normal. Indeed, for this reason, the Nevada State Athletic Commissions (NSAC) banned testosterone replacement therapy in biological males in the Ultimate Fighting Championships (UFC) in 2014 [61,80].

Future Direction and Recommendations for TGD Sport Policies
The 2021 IOC Framework on Fairness, Inclusion and Non-discrimination promotes ten principles, primarily focusing on inclusion and non-discrimination, for sport federations to consider when organising sporting events [2]. Current considerations for the participation of transgender and gender-diverse athletes receiving gender-affirming hormone therapy (GAHT) in competitive sports are based predominantly on current serum testosterone levels. Testosterone-related performance enhancement may persist in some sports through the retention of physical advantage or muscular strength even after the normalisation of serum levels in trans women athletes [12,81]. The use of current testosterone levels has limitations, as previously discussed, and sport organisations should consider whether using current testosterone as a marker of competitive fairness fulfils their policy aims.
Further investigation into testosterone replacement in trans male athletes is required. This is of particular importance in weight-based sports, where the athlete might not be exposed to the testosterone fluctuations associated with weight changes that occur as part of the RED-S spectrum. The impact of anthropometric variables on sporting ability also likely requires further investigation. Clear policies for monitoring testosterone levels and anthropometric variables in TGD athletes should, therefore, be put in place by all sporting organisations if such policies enable TGD athletes to compete in a class other than that of their biological sex. A clear process for the management of levels lying outside of the proposed testosterone serum range should be developed, with clear guidelines on how abnormal results will be managed. Additionally, under the new 2021 IOC Framework on Fairness, Inclusion and Non-discrimination, male advantage over female athletes cannot be assumed in all sports. Studies have reported advantages in many sports in which power, strength and endurance are directly related to performance [25][26][27][28]. In some sports, further studies may be required; for example, motorsports or snooker. Sport organisations also need to specify the transitioning requirements for both pre-and post-puberty adolescent athletes, and all future transgender policies should include a pre-and post-puberty adolescent athlete section, as well as TGD policies for competitive and recreational sport. A section should also be included in all policies to define the term "transgender" for the purposes of the policy, and separate policies should be developed for intersex and DSD athletes. Additionally, when policies are finalised, consultation involving relevant stakeholders within the sport should take place and relevant external contributors should be allowed to offer input.

Limitations
This article provides a comprehensive overview of TGD athlete policies across UK sports and identifies areas of similarity and discrepancy. However, TGD policies outside the UK were not considered in this scoping review, although we recognise the recent TGD policy changes by the UCI [42] and Federation Internationale de Natation (FINA) [43], which will likely be reflected in UK TGD policies. Future scoping reviews could investigate and compare TGD policies from organisations outside of the UK. As different physiological requirements exist across various sports, TGD policies will likely differ between sports. It was beyond the scope of this paper to recommend TGD policies for each sport, and the paper rather aimed to highlight areas where a consistent approach to TGD athletes and sport participation is needed or could be useful. This review did not include policies related to para-athletes in UK sport; this is a topic for further investigation. TGD policy is a rapidly evolving field in sport medicine, and this scoping review therefore only provides a snapshot of sports' current TGD policies, which are currently evolving.

Conclusions
This scoping review showed a lack of consistency and clear guidelines among UK sporting organisations in managing transgender and gender-diverse (TGD) athletes in competitive sports. Similar reviews investigating TGD policies outside of the UK should be considered. One area that policies for transgender athlete participation need to address is the appropriateness of using testosterone levels as a marker of performance advantage, as retained strength and anthropometric advantages are independent of current testosterone levels. Sporting federations need to develop their transgender policies with input from medical personnel, as well as the wider multi-disciplinary team and external agencies. Policies should consider the need for pre-and post-puberty guidelines, as well as guidelines for both competitive and recreational sport activities. Greater scrutiny needs to be given to trans men athletes regarding their testosterone levels, and sport-specific protocols should be established for how these testosterone levels will be monitored in transgender athletes, with clear rules for competitive sport exclusion based on them. Further studies on transitioning and transgender athletes aimed at understanding the impact of TGD athletes in their respective sports-and the potential impact of transitioning athletes on biologically female athletes' safety, competitive opportunities and participation in sport at every level-will provide further information to help with policy making in this area. This is a challenging area for policymakers, and it is important that sport organisations are well-informed, undertake diverse considerations and consult widely in the further development and evolution of their sport's TGD policy.

Data Availability Statement:
The data presented in this study are available on request from the corresponding author.

Conflicts of Interest:
The authors declare no conflict of interest.